Bit selection

[ttwark]

I have been cutting melamine by the unit for years. Always use 3/8 solid carbide compression bit from Centurion Tool. I get 30 or so sheets before bit change. I have recently started buying panels with the Plam already applied from the distributor. I am only getting a few sheets cut before I have a nice little groove worn in the bit from the Plam. Is there any advice from your direct experiences that might improve bit life?

[coryatjohn]

Can you move the Z up and down a tiny bit to spread out the wear? It wouldn't take much, probably +/-.01 a couple of times per sheet. Totally a guess though.

[dlcw]

I have been cutting melamine by the unit for years. Always use 3/8 solid carbide compression bit from Centurion Tool. I get 30 or so sheets before bit change. I have recently started buying panels with the Plam already applied from the distributor. I am only getting a few sheets cut before I have a nice little groove worn in the bit from the Plam. Is there any advice from your direct experiences that might improve bit life?

I had a large job (about 75 sheets) a couple of years ago cutting Plam for a customer. I suffered from the same issue. Other then raise or lower the bit about .040" every couple of sheets (change your toolpath Z), there's not a whole lot you can do. That is what I did and I was able to get about 7 sheets before the bit was shot. Don't plan on getting the number of sheets per bit that you get with melamine.

I changed my Z height by zeroing to the z-zero plate and progressively putting shims under it to change the Z height. I started where the top of the up cut spiral was just at the underside edge of the sheet. By adding the shims, I was able to "walk" the bit up a little at a time until I had only about .01" cutting through the bottom of the sheet. Very tedious....

That Plam is hell on bits. I don't think metal cutting bits would even stand up to it. That was the first and last Plam job I am going to do....

[ntraub01]

Because you are using a compression bit is it safe to think that you are cutting the material in a single pass?? Can you use a spoilboard and a much less expensive down-cut spiral bit which would be less expensive to replace if necessary AND you are still going to get a good finished edge on both the top and the bottom of the material. I'm wondering if it wouldn't actually alleviate the issue with the Plam routing an edge into the bit because the edge would eventually be cleaned by the undamaged portion of the bit as it continues to step down into the material?!?! Just thinking outloud...

[curtiss]

Seems this one is popular with cabinet work

http://www.vortextool.com/index.cfm?fuseaction=category.display&category_id=31&CFID=2782167&CFTOKEN=2c73a3f5159b901b-F4041770-979B-93F4-C253C7716A49C540

they can be sent back in to be re-sharpened.

[jerry_stanek]

Seems this one is popular with cabinet work

http://www.vortextool.com/index.cfm?fuseaction=category.display&category_id=31&CFID=2782167&CFTOKEN=2c73a3f5159b901b-F4041770-979B-93F4-C253C7716A49C540

they can be sent back in to be re-sharpened.

If they are getting a groove in the bit then the bit is pretty much done. you may want to look at these

http://www.toolstoday.com/p-5729-diamond-tipped-pcd-compression-router-bit-updown-shear-with-carbide-plunge-point-rh-rotation.aspx?variantids=8942,0

[dlcw]

Seems this one is popular with cabinet work

http://www.vortextool.com/index.cfm?fuseaction=category.display&category_id=31&CFID=2782167&CFTOKEN=2c73a3f5159b901b-F4041770-979B-93F4-C253C7716A49C540

they can be sent back in to be re-sharpened.

I've been cutting plywood and composites on my CNC for 5 years now. One thing I learned was that sharpening bits never yields a result that is fiscally sound. When I was sharpening bits I noticed they were never as sharp and cut maybe 1/2 to 2/3 the number of sheets as a new bit. With the sharpening costs being 2/3 that of a new compression bit, I decided it wasn't worth the money to sharpen anymore. That is my experience.

[ssflyer]

Tom,

What software are you using for your toolpaths? One option, in Vectric's Aspire or VCarve Pro, would be to use a spiral ramp for your cutouts. MIght take some tweaking, as you would want to start deep enough for the up spiral section to be below the surface, and could add a little time to your procedure, but will definitely eliminate the grove in your bits.